Support devices, utilized in spinal surgery, often include screws driven through the bones in the spinal column. The screws are subsequently connected by way of a metal rod or a plate after the screws have been inserted. These rods or plates are typically inserted through the screw heads, having complex mechanical connections, allowing for variable fixation angles. This approach, using variable angle screw heads, requires the heads to align to accommodate for an arc of a pre-defined radius. This enables the delivery of the connecting rod, shaped as an arc or a circle, with the same radius.
However, there are a number of shortcomings with such systems. For example, both screw heads have to be able to pivot to adjust for the fixed trajectory of the connecting rod. Additionally, because the extensions from the screws need to be secured to the device at a single point, there is limited flexibility when positioning the device, making it more difficult to set up. Furthermore, because the prior art devices require that the screw extensions meet at a single point, manipulation of the screw heads and connecting rods involves more movement under the patient's skin and muscle, requiring substantially higher surgical skills and experience as well as a larger surgical incision through the patients back muscles, relative to currently practiced methods for such surgeries.